The most exciting part of “F(l)ag Football” arrives at the end, when two bitter rivals face each other. But the most insightful scene comes in the middle of this documentary, when the New York Warriors of the National Gay Flag Football League take on a straight team from Long Island.

The Long Island players aren’t told that most of the Warriors are gay, and excerpts shown from the game — no spoilers on the winner — feature some intense competition. After one Long Islander learns of the opposing players’ sexuality, he reacts with a shrug and with praise for their skills.

That’s how you want life to be: people judged on their abilities and without foolish preconceptions. And if we’re not there yet, this likable film at least offers several optimistic moments as Seth Greenleaf, the director, follows the Warriors, the L.A. Motion and other teams as they train for the yearly Gay Bowl flag football tournament. (The game, a variation on touch football, places a premium on speed; players are downed not by tackles, but when an opponent pulls a marker from the ball carrier’s belt.)

Along the way, we listen to coming-out stories and look into the conflict between traditional views of masculinity, especially in sports (and in the N.F.L. in particular), and stereotypes of homosexuality. It’s an interesting mix, though a few of the interviews meander, and, except for the championship, there’s little sense of urgency onscreen.

The film gains momentum, however, as the athletes experience hope, disappointment, pain and joy during the final contest. It should go without saying, but Mr. Greenleaf knows it’s worth showing: On the field and off, we are all so much alike.